First, ammonium nitrogen fertilizer should not be mixed with alkaline fertilizer. Because of the ammonia gas volatilization and the effect of reducing fertilizer after mixing. Commonly used nitrogenous nitrogen fertilizers include ammonium bicarbonate, ammonium sulfate, ammonium nitrate, ammonium acid, ammonium nitrate, etc., and alkaline fertilizers include calcium and magnesium fertilizer, grass ash, lime, and the like.

Second, nitrate nitrogen fertilizer should not be mixed with organic fertilizer. Organic fertilizers contain more organic matter, and in the case of nitrate-nitrogen fertilizers, nitrification occurs under the action of denitrifying bacteria, and nitrogen is lost. Commonly used nitrate nitrogen fertilizers are ammonium nitrate, sodium nitrate, calcium ammonium nitrate and the like.

Third, nitrate nitrogen fertilizer should not be applied in rice fields. Under anaerobic conditions, nitrate-nitrogen fertilizer is easily decomposed by denitrifying bacteria to cause nitrogen loss, and the separated silver nitrate is lost with water, which reduces fertilizer efficiency. Dry land should also be prohibited from being poured before or after heavy rain.

Fourth, urea should not be poured. Because after being applied to the soil, urea will hydrolyze to ammonium bicarbonate through the action of soil microorganisms, and then decompose ammonia to volatilize.

Fifth, urea should not be close to the seed. Urea contains a small amount of biuret, which affects seed germination. When the concentration is too high, the seed will be poisoned. When using urea as a seed fertilizer, do not directly contact the seeds or control the amount of urea applied, and should not exceed 2.5 kg per acre.

Sixth, the concentration of urea as a root dressing should not be too high. Used as a foliar fertilizer, the urea effect is really good, but blindly increasing the amount will be counterproductive. The suitable application concentration is 0.8--1% for grain and cotton crops and 0.4--0.6% for high-efficiency economic crops of fruit and vegetable tea.

Seven is that ammonium bicarbonate should not be applied to the table for too long. Avoid shallow application, the nature of ammonium bicarbonate is unstable, and should be covered immediately after application.

Eight is that ammonium sulfate is not suitable for long-term application. Ammonium sulfate is an acidic fertilizer, and long-term application will increase soil acidity and damage soil structure. Applied at. On calcareous soil, sulfate ions will bind the soil with calcium melon. Therefore, it should be applied alternately with other nitrogen fertilizers.

Nine is ammonium sulfate is not suitable for application in paddy fields. Because it will fall into the oxygen-deficient reducing layer after application, the sulfate is reduced to hydrogen sulfide, and black ferrous sulfate is formed around the rice root to form black roots and nutrient loss.

Ten is that ammonium nitride should not be applied to the nitrogen crop. Application to the nitrogenous crops such as sweet potato, sugar beet, and potato, citrus, grape, tobacco, etc. will cause side effects, causing damage to the physiological functions of the crop, and even death, and the quality of the harvest will be reduced.